The Blades manager knows it will be tough for his team to repeat their heroics of this season, which saw them finish in the top half after promotion.
And he hopes his team can invest in the summer to improve the quality of the first 11 and squad as they go again in September.
"It's a feeling like we had when we first got into the Championship, we just faded away towards the back end of the season," Wilder told Sky Sports after a 3-1 loss to Southampton on the final day of the season.
"We have to come stronger next year, we have to recruit well in the summer, we have to improve the players we've got here, and bring better players in if we want to be an established Premier League football club.
"It's been a hell of a long season for us, with everybody else, we've been stretched as a squad, you've seen the players out there late on. The players have given everything for the football club, so I can't be too critical of them.
"We've come to Southampton today and you look at the players they've got, and we've finished above them. I'm not trying to deflect anything, what I'm saying is that to continue the journey, we have to recruit well and improve on the players and bring better players in to compete.
"We looked stretched today, we looked tired, and that's what happened when you give time and space to really good players, they punished us and we didn't punish them."